If variable manufacturing costs are \( \$ 11 \) per unit and total fixed manufacturing costs are \( \$ 239,400 \), what is the manufacturing cost per unit if: a. 4,200 units are manufactured and the company uses the variable costing concept? \( \$ \) b. 5,700 units are manufactured and the company uses the variable costing concept? \$ c. 4,200 units are manufactured and the company uses the absorption costing concept? \$ d. 5,700 units are manufactured and the company uses the absorption costing concept? q